Resetting tool for memory alloy pin puller
By converting the rotational motion of the nut into the linear motion of the pull rod through threaded transmission, the problem of unstable reset of the single-stroke shape memory alloy wire under high and low temperature conditions is solved, thus realizing stable reset and improved reliability of the shape memory alloy pin puller.
Patent Information
- Application Number
- CN202512042539.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-02-24
AI Technical Summary
In the existing technology, the reset of a single-pass shape memory alloy wire is unstable, especially under high temperature and low temperature conditions, making it difficult to guarantee the complete reset of the shape memory alloy puller, and the spring force design margin is limited.
The rotational motion of the nut is converted into the linear motion of the pull rod by using threaded transmission. The threaded connection and limiting structure realize the stable reset of the single-pass shape memory alloy wire, and the threaded transmission provides a constant tension.
Stable reset of the shape memory alloy pin puller is achieved. The structure is simple and compact, and the operation is convenient. It avoids the problem of incomplete reset caused by structural size limitations and improves the reliability of reset.
Smart Images
Figure CN121552289A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of aerospace technology, and in particular to a memory alloy pin puller reset tool. Background Technology
[0002] Currently, most non-pyrotechnic star-launch separation mechanisms use shape memory alloy wires as actuators, with actuator types categorized as single-stroke, double-stroke, and full-stroke. Single-stroke shape memory alloy wires can only move in one direction and cannot recover after movement, but their technology is relatively mature, their performance is stable, and their structure is simple and reliable. Double-stroke shape memory alloy wires can reciprocate on their own and can be recycled, but their performance is not stable enough, and their application and control are also more complex. Full-stroke shape memory alloy wires are similar to double-stroke shape memory alloy wires, but the memory effect of full-stroke shape memory alloy wires is completely reversed under high and low temperature conditions, which is not conducive to ensuring performance stability.
[0003] At low temperatures, the internal microstructure of a single-pass shape memory alloy (SMI) wire is in a martensitic state. At this temperature, an external load needs to be applied to the wire for pre-stretching, causing plastic deformation. After removing the load, heating the deformed wire reduces or eliminates the plastic deformation, restoring it to its original shape. Based on this, most current spacecraft separation mechanisms use a combination of SMI wire and spring in their shape memory pin pullers. By designing the spring force, the wire can be driven by the spring at low temperatures, achieving automatic reset. Upon heating, the wire, in turn, pushes the spring, storing energy.
[0004] However, it is usually difficult to achieve the predetermined plastic deformation of the single-pass shape memory alloy wire in the shape memory alloy puller in the initial state solely by the spring force; and since the spring force is not constant, it is difficult to guarantee the stable reset of the single-pass shape memory alloy wire. In addition, due to the size limitations of the shape memory alloy puller, the design margin of its spring force is limited by the size, so in some cases, the single-pass shape memory alloy wire may not be fully reset after heating due to the limited spring force.
[0005] Therefore, how to stably reset a shape memory alloy puller using a single-pass shape memory alloy wire is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0006] This application provides a memory alloy pin puller reset fixture, which converts the rotational motion of the nut into the translational motion of the pull rod through thread transmission, thereby achieving plastic deformation of the single-pass shape memory alloy wire in the initial low temperature state and after heating. It has the advantages of simple and compact structure, constant force, reliable operation and convenient operation.
[0007] To solve the above-mentioned technical problems, this application provides the following technical solution:
[0008] A memory alloy pin puller reset fixture includes: a fixture fixing plate, a pin puller fixing bracket, a nut, a pull-out rod, two pull-out rod fixing plates, a limit bolt, and a fixing screw; wherein, the lower end face of the pin puller fixing bracket is fixedly connected to the upper surface of the fixture fixing plate, and the upper end face of the pin puller fixing bracket has a downwardly recessed dividing groove, dividing the upper part of the pin puller fixing bracket into a nut blocking wall plate and a pin puller fixing wall plate that are parallel to each other; the middle section of the pull-out rod is threadedly connected to the nut, and the right section of the pull-out rod passes through a pulling hole in the nut blocking wall plate and extends into the pin puller fixing wall plate. The reset hole is threaded to the threaded connection hole on the pin head of the shape memory alloy pin puller; the upper surface of the tooling fixing plate has a downward recessed groove parallel to the nut blocking wall plate and the pin puller fixing wall plate; the pull rod fixing plate has a vertically extending upright plate and a horizontally extending horizontal plate from the lower end of the upright plate to one side, the horizontal plate is located in the groove, and the fixing screw passes through the positioning hole on the horizontal plate and is screwed into the fixing hole in the groove; the limiting bolt passes through the limiting shaft hole on the upright plate and the elongated hole on the left section of the pull rod with the same extension direction as the pull rod axis, and the left section of the pull rod is located between the two upright plates.
[0009] In the memory alloy pin puller reset fixture described above, preferably, the pin puller fixing plate has pin puller fixing holes that pass through the left and right sides, and the pin puller fixing holes are distributed around the reset hole for fixed connection with the housing of the memory alloy pin puller.
[0010] In the memory alloy pin puller reset fixture described above, preferably, the portion of the pin puller fixing frame near its lower end face extends to both sides to form fixing wings. The fixing wings have mounting holes that pass through the upper and lower sides. By inserting screws into the mounting holes and screwing them into the fixture fixing plate, the pin puller fixing frame and the fixture fixing plate are fixed.
[0011] In the memory alloy pin puller reset fixture described above, preferably, each fixed wing has two mounting holes.
[0012] In the memory alloy pin puller reset fixture described above, preferably, a stiffener is connected between the fixed wing on one side of the nut blocking wall plate and the nut blocking wall plate, and a stiffener is connected between the fixed wing on one side of the pin puller fixed wall plate and the pin puller fixed wall plate.
[0013] In the memory alloy pin puller reset fixture described above, preferably, the left section of the pull rod has two opposing limiting planes, and an elongated hole penetrates both limiting planes.
[0014] In the memory alloy pin puller reset fixture described above, preferably, the left section of the pull rod is thicker than the middle section of the pull rod, and the middle section of the pull rod is thicker than the right section of the pull rod.
[0015] In the memory alloy pin puller reset fixture described above, preferably, the thickness of the nut is greater than the thickness of a standard nut with the same hole diameter.
[0016] In the memory alloy pin puller reset fixture described above, preferably, the upper part of the side of the upright plate away from the horizontal plate is recessed towards the direction of approaching the horizontal plate, and the lower part of the side plate protrudes towards the direction of away from the horizontal plate, so that the lower parts of the upright plates of the two pull-out rod fixing plates contact each other, and there is a certain space between the upper parts of the upright plates of the two pull-out rod fixing plates for accommodating the left section of the pull-out rod.
[0017] In the memory alloy pin puller reset fixture described above, preferably, a stiffening plate connects the vertical plate and the horizontal plate.
[0018] Compared to the aforementioned background technology, the memory alloy pin puller reset fixture in this application uses relatively simple components to convert the rotational motion of the nut into the linear motion of the pull rod. It can provide a large pulling force with a small thread force, has a simple and compact structure, and high reliability. It avoids the problem that the spring force cannot make the single-pass shape memory alloy wire return to the correct position due to the size limitation of the structure itself. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.
[0020] Figure 1 This is a front view of the shape memory alloy pin puller reset fixture provided in this application;
[0021] Figure 2 This is a perspective view of the shape memory alloy pin puller reset fixture provided in this application;
[0022] Figure 3 This is a schematic diagram of the pin puller fixing bracket of the shape memory alloy pin puller reset fixture provided in this application;
[0023] Figure 4 This is a schematic diagram of the shape memory alloy pin puller before reset provided in this application;
[0024] Figure 5 This is a schematic diagram of the shape memory alloy pin puller after reset provided in this application;
[0025] Figure 6 This is a schematic diagram of the pull-out rod of the memory alloy pin puller reset fixture provided in this application;
[0026] Figure 7 This is a schematic diagram of the pull-out rod fixing plate of the memory alloy pin puller reset fixture provided in this application. Detailed Implementation
[0027] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.
[0028] like Figure 1 and Figure 2 As shown, this application provides a memory alloy pin puller reset fixture, including: a fixture fixing plate 10, a pin puller fixing bracket 20, a nut 30, a pull-out rod 40, two pull-out rod fixing plates 50, a limit bolt 60, and a fixing screw 70.
[0029] like Figure 3 As shown, the lower end face of the pin puller fixing bracket 20 is fixedly connected to the upper surface of the tooling fixing plate 10. The upper end face of the pin puller fixing bracket 20 has a downwardly recessed dividing groove that does not penetrate to the lower end face of the pin puller fixing bracket 20, thereby dividing the upper part of the pin puller fixing bracket 20 into a nut blocking wall plate 21 and a pin puller fixing wall plate 22 that are parallel to each other. The nut blocking wall plate 21 has a pull hole 211 that passes through the left and right sides, and the pin puller fixing wall plate 22 has a reset hole 222 that passes through the left and right sides. The pull hole 211 and the reset hole 222 are coaxially arranged.
[0030] Optionally, the pin puller fixing plate 22 is further provided with pin puller fixing holes 221 that pass through both the left and right sides, and the pin puller fixing holes 221 are distributed around the reset hole 222 for fixed connection with the housing of the shape memory alloy pin puller 80. Alternatively, the pin puller fixing plate 22 is provided with two pin puller fixing holes 221, and these two pin puller fixing holes 221 are symmetrically distributed on both sides of the reset hole 222. Still alternatively, the two pin puller fixing holes 221 and the reset hole 222 are located on the same horizontal line, thereby facilitating the fixed connection of the housing of the shape memory alloy pin puller 80 to the pin puller fixing plate 22.
[0031] Optionally, the portion of the pin puller fixing bracket 20 near its lower end face extends to both sides to form fixing wings 23, making the shape of the pin puller fixing bracket 20 "┸" shaped, thereby increasing the area of the lower end face of the pin puller fixing bracket 20, which is beneficial to the stable fixing of the pin puller fixing bracket 20 and the tooling fixing plate 10. Optionally, the fixing wings 23 are provided with mounting holes 231 that pass through the upper and lower sides, and screws are inserted into the mounting holes 231 and screwed into the tooling fixing plate 10 to fix the pin puller fixing bracket 20 and the tooling fixing plate 10. Optionally, each fixing wing 23 is provided with two mounting holes 231 to make the fixing of the pin puller fixing bracket 20 and the tooling fixing plate 10 more secure. Optionally, a stiffening rib 24 connects the fixing wing 23 on one side of the nut blocking plate 21 to the nut blocking plate 21, and a stiffening rib 24 also connects the fixing wing 23 on one side of the pin puller fixing plate 22 to the pin puller fixing plate 22, to make the structure of the pin puller fixing bracket 20 more stable. Alternatively, the stiffening rib 24 is located between the two mounting holes 231 on the fixing wing 23 to which it is connected.
[0032] like Figure 4 and Figure 5 As shown, the shape memory alloy pin puller 80 unlocks and separates by actuating the pin head 82 through a single-pass shape memory alloy wire inside its housing 81. The housing 81 has outwardly extending ear plates 811 with connecting holes for engaging with pin puller fixing holes 221 on the pin puller fixing plate 22, thus securing the housing 81 of the shape memory alloy pin puller 80 to the fixing plate 22. The pin head 82 is a cylindrical metal rod with a threaded connecting hole 821 at the center of its outer end face. In the initial low-temperature state, the outer end face of the pin head 82 is flush with the end face of the housing 81 of the shape memory alloy pin puller 80, requiring the single-pass shape memory alloy wire of the shape memory alloy pin puller 80 to reset. After heating, the outer end face of the pin head 82 also remains flush with the end face of the housing 81 of the shape memory alloy pin puller 80, again requiring the single-pass shape memory alloy wire of the shape memory alloy pin puller 80 to reset. When the shape memory alloy pin puller 80 needs to be reset, the housing 81 of the shape memory alloy pin puller 80 will be fixedly connected to the pin puller fixing plate 22, and the end face of the housing 81 of the shape memory alloy pin puller 80 will be inserted into the reset hole 222.
[0033] like Figure 6As shown, both the right section 41 and the middle section 42 of the pull-out rod 40 are threaded sections, meaning that both the right section 41 and the middle section 42 of the pull-out rod 40 are provided with external threads. The middle section 42 of the pull-out rod 40 is threadedly connected to the nut 30. The right section 41 of the pull-out rod 40 passes through the pull hole 211 on the nut blocking wall plate 21 and extends into the reset hole 222 on the pin puller fixing wall plate 22, where it is threadedly connected to the threaded connection hole 821 on the pin head 82. It also positions the nut 30 on the left side of the nut blocking wall plate 21. The left section 43 of the pull-out rod 40 has an elongated hole 431 extending in the same direction as the axial direction of the pull-out rod 40, for passing through the limit bolt 60.
[0034] Optionally, the left segment 43 of the pull-out rod 40 has two opposing limiting planes 432, and an elongated hole 431 penetrates these two limiting planes 432, thereby allowing the pull-out rod 40 to move in the pull-out direction (e.g., ...). Figure 1 When moving (in the direction indicated by the middle arrow A), the pull rod 40 can prevent rotation by contacting the limiting plane 432 with the pull rod fixing plate 50. Alternatively, the pull rod 40 can be a stepped cylindrical shape, meaning the left section 43 is thicker than the middle section 42, and the middle section 42 is thicker than the right section 41. This ensures both the threaded connection between the right section 41 and the threaded connection hole 821 on the pin head 82, and the strength of the middle section 42 and the left section 43. Alternatively, the nut 30 can be a non-standard nut, meaning its thickness is greater than that of a standard nut with the same hole diameter, facilitating the tightening operation of the nut 30.
[0035] like Figure 7 As shown, the pull-out rod fixing plate 50 has a vertically extending upright plate 51 and a horizontally extending horizontal plate 52 extending to one side from the lower end of the upright plate 51, so that the shape of the pull-out rod fixing plate 50 is "L" shaped; the upright plate 51 has a limiting shaft hole 511 passing through both sides, and the horizontal plate 52 has a positioning hole 521 passing through both sides; the upper surface of the tooling fixing plate 10 has a downwardly recessed groove 11 located on the left side of the pin puller fixing bracket 20, the groove 11 is parallel to the nut blocking wall plate 21 and the pin puller fixing wall plate 22, and the groove 11 has two fixing brackets. The holes are not shown in the figure; the horizontal plates 52 of the two pull-out rod fixing plates 50 are both located in the slide groove 11 and can slide in the slide groove 11. The fixing screws 70 pass through the positioning holes 521 on the horizontal plates 52 and are screwed into the fixing holes in the slide groove 11, thereby fixing the pull-out rod fixing plates 50 to the tooling fixing plates 10; the limiting bolts 60 pass through the limiting shaft holes 511 on the vertical plates 51 of the two pull-out rod fixing plates 50 and the elongated holes 431 on the left section 43 of the pull-out rod 40, so that the pull-out rod 40 can only move in its pull-out direction.
[0036] Optionally, the upper portion of the side of the upright plate 51 away from the horizontal plate 52 is recessed towards the horizontal plate 52, while the lower portion of this side protrudes away from the horizontal plate 52, thus creating a stepped shape between the upper and lower portions of this side. This allows the lower portions of the upright plates 51 of the two pull-out rod fixing plates 50 to contact each other, while providing a space between the upper portions of the upright plates 51 of the two pull-out rod fixing plates 50 to accommodate the left section 43 of the pull-out rod 40. Alternatively, a reinforcing rib 53 can be connected between the upright plate 51 and the horizontal plate 52 to increase the strength of the pull-out rod fixing plate 50.
[0037] When resetting the shape memory alloy pin puller 80 using the shape memory alloy pin puller reset fixture of this application, first insert the end face of the shell 81 of the shape memory alloy pin puller 80 into the reset hole 222, and fix the shell 81 of the shape memory alloy pin puller 80 to the pin puller fixing plate 22; then tighten the nut 30 to the middle section 42 of the pull rod 40, pass the right section 41 of the pull rod 40 through the pull hole 211 on the nut blocking plate 21, and insert it into the reset hole 222 on the pin puller fixing plate 22 to thread it into the threaded connection hole 821 on the pin head 82, and make the nut 30 located on the left side of the nut blocking plate 21; then, the two pull rod fixing plates 5 The horizontal plate 52 of the 0 is placed in the groove 11 of the tooling fixing plate 10, and the two pull-out rod fixing plates 50 are slid towards each other until their vertical plates 51 are attached to the left section 43 of the pull-out rod 40. The fixing screws 70 are passed through the positioning holes 521 on the horizontal plate 52 and screwed into the fixing holes in the groove 11, thereby fixing the pull-out rod fixing plates 50 to the tooling fixing plate 10. Then, the limiting bolts 60 are passed through the limiting shaft hole 511 on the vertical plate 51 of one pull-out rod fixing plate 50, the elongated hole 431 on the pull-out rod 40, and the limiting shaft hole 511 on the vertical plate 51 of the other pull-out fixing plate 50, thereby limiting the pull-out rod 40 and completing the installation of each component.
[0038] Next, rotate the nut 30 until it is flush with the nut stop plate 21, and then continue to rotate the nut 30 using a wrench (as shown). Figure 1 (in the direction indicated by the middle arrow B), because the nut 30 is restricted by the nut blocking plate 21, the pull rod 40 moves in the pull-out direction (as shown by the middle arrow B). Figure 1 (In the direction indicated by the middle arrow A) the pin head 82 moves outward under the action of the pull rod 40, thereby causing the single-pass shape memory alloy wire in the housing 81 of the shape memory alloy pin puller 80 to reset.
[0039] In this process, the principle of thread transmission is utilized to rotate the nut while keeping its position stationary, thereby converting the torque generated by the rotation of the nut into axial tension through the threaded pair, thus resetting the single-pass shape memory alloy wire inside the shape memory alloy pin puller housing.
[0040] The memory alloy pin puller reset fixture, constructed using this principle, is simple and compact in structure, with low manufacturing and maintenance costs. Furthermore, this fixture utilizes the constant tension of the threaded drive reset to ensure continuous and uniform movement.
[0041] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0042] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A memory alloy pin puller reset fixture, characterized in that, include: Tooling fixing plate, pin puller fixing bracket, nut, pull-out rod, two pull-out rod fixing plates, limit bolt and fixing screw; The lower end face of the pin puller fixing frame is fixedly connected to the upper surface of the tooling fixing plate. The upper end face of the pin puller fixing frame has a downwardly recessed dividing groove, which divides the upper part of the pin puller fixing frame into a nut blocking wall plate and a pin puller fixing wall plate that are parallel to each other. The middle section of the pull rod is threadedly connected to the nut, and the right section of the pull rod passes through the pull hole on the nut blocking plate and extends into the reset hole on the pin puller fixing plate to be threadedly connected to the threaded connection hole on the pin head of the shape memory alloy pin puller. The upper surface of the tooling fixing plate has a groove that is recessed downward and parallel to the nut blocking wall plate and the puller fixing wall plate. The pull rod fixing plate has a vertically extending upright plate and a horizontally extending horizontal plate from the lower end of the upright plate to one side. The horizontal plate is located in the groove. The fixing screw passes through the positioning hole on the horizontal plate and is screwed into the fixing hole in the groove. The limiting bolt passes through the limiting shaft hole on the upright plate and the elongated hole on the left section of the pull rod, with the extension direction being the same as the pull rod axis, and the left section of the pull rod is located between the two upright plates.
2. The shape memory alloy pin puller reset fixture according to claim 1, characterized in that, The pin puller fixing plate has pin puller fixing holes that pass through the left and right sides, and the pin puller fixing holes are distributed around the reset hole for fixed connection with the housing of the shape memory alloy pin puller.
3. The shape memory alloy pin puller reset fixture according to claim 1 or 2, characterized in that, The pin puller fixing bracket extends to both sides near its lower end face to form fixing wings. The fixing wings have mounting holes that pass through the upper and lower sides. The pin puller fixing bracket is fixed to the tooling fixing plate by inserting screws into the mounting holes and screwing them in.
4. The shape memory alloy pin puller reset fixture according to claim 3, characterized in that, Each fixed wing has two mounting holes.
5. The shape memory alloy pin puller reset fixture according to claim 3, characterized in that, A stiffening plate connects the fixed wing on one side of the nut blocking plate to the nut blocking plate, and a stiffening plate connects the fixed wing on one side of the pin puller fixing plate to the pin puller fixing plate.
6. The shape memory alloy pin puller reset fixture according to claim 1 or 2, characterized in that, The left section of the pull rod has two opposing limiting planes, and an elongated hole penetrates both limiting planes.
7. The shape memory alloy pin puller reset fixture according to claim 1 or 2, characterized in that, The left section of the pull rod is thicker than the middle section, and the middle section of the pull rod is thicker than the right section.
8. The shape memory alloy pin puller reset fixture according to claim 1 or 2, characterized in that, The thickness of the nut is greater than that of a standard nut with the same bore diameter.
9. The shape memory alloy pin puller reset fixture according to claim 1 or 2, characterized in that, The upper part of the side of the upright plate away from the horizontal plate is recessed towards the horizontal plate, and the lower part of the side plate protrudes away from the horizontal plate, so that the lower parts of the upright plates of the two pull-out rod fixing plates contact each other, and there is a certain space between the upper parts of the upright plates of the two pull-out rod fixing plates to accommodate the left section of the pull-out rod.
10. The shape memory alloy pin puller reset fixture according to claim 1 or 2, characterized in that, The vertical and horizontal panels are connected by stiffening plates.